One other name I might throw out there is Martin O'Malley. If he does in fact run for President, look for Clinton to shrewdly assess how he handles the white heat of a national race and the media vetting process. If he shows strong candidate skills, no big skeletons emerge and he doesn't go too negative on her, he might very well get serious consideration. He's compiled a considerable record as governor of Maryland and the base will like him.

My guess is that Clinton will put a high value on executive and/or legislative accomplishment.

I would agree with the consensus here that Mark Warner and Tim Kaine are the two obvious choices. They would be relatively safe picks and Clinton is known for caution. Both are former governors/current senators of a key swing state. And Gov. Terry McAuliffe would appoint a successor in the Senate so no trouble there. Warner has stronger political standing in Virginia but also carries more political baggage than Kaine.

My problem with a Sherrod Brown pick, although I like him a great deal, is that Gov. Kasich is likely to win reelection this November and would appoint his successor.

If Clinton is willing to take a risk (doubtful) then I would say the best choices would be either Julian Castro or Kirsten Gillibrand. Gillibrand has developed a solid record in the Senate, has gotten some media buzz and I suspect she would love to run nationally. Clinton places a high value on loyalty and Gillibrand has been loyal from the start (she cut her teeth in politics working on Hillary's 2000 Senate campaign). Her work for women's rights would reinforce Clinton's message, similar to what Bill did with Al Gore in '92.

I'm less familiar with Castro's record. From what I've seen he has huge potential and the demographic appeal is obvious. But I'm not sure he'll have had enough time to develop his credentials.

I don't understand it either. He quit after one term and reportedly hated/was terrible at retail politics. Has he somehow picked up a taste for retail politics since he retired? Otherwise Iowa and New Hampshire will go badly.

We should be wary of these latest Quinnipiac surveys. Not only are the results the most Republican-friendly of the year in either state, but Quinnipiac’s polls have previously been too pro-Republican at this point in midterm elections. Its likely voter polls in 2010 had Republican Tom Foley up by 9 percentage points in the Connecticut gubernatorial race; he lost by a point. Quinnipiac had Democrat Andrew Cuomo up by just 6 points in the New York gubernatorial race; he won by 29 points. It had Republican John Kasich up by 17 points in the Ohio gubernatorial race; he won by just 2 points.

In this most recent poll with with Gardner up +8, Quinnipiac only included Latino voters as 8% of the sample. So in the last two months, they have decided that the Latino share of the electorate will drop by about 38%! And as others have mentioned, this poll is weighted at 34% R / 27% D.http://www.quinnipiac.edu/images/polling/co/co09172014_demos_czm75h.pdf

I don't know the reason for these changes, but the current poll's sample has been shifted to be extremely GOP friendly. No wonder Hickenlooper and Udall did so poorly.

People need to keep things in perspective and not panic. This Suffolk poll has Gardner up by a single point. The last poll Gardner led in was done by Quinnipiac back in July. Since then Sen. Udall has led in seven polls. Unless Suffolk is confirmed by multiple other pollsters this is just statistical noise. I am still confident Sen. Udall will win reelection.

Hagan has made courting women voters, especially single women, the backbone of her campaign -- "heels on the ground" was what she called it -- and it shows, with a 49-33 edge among women, similar to what other polls have shown.

A four-point lead isn't much given the dynamics of the race--sixth year election vulnerable incumbent, pink/purple state, very unpopular Democrat in White House, older and whiter electorate. I'll buy the notion that CO, NC, and IA all tilt to the Democrat right now. But I just don't buy the idea that they'll likely stay that way in a year like this.

The Republican Party brand is also deeply unpopular nationally and while that may not matter much in solid Republican states, the swing states are a different story. There is a reason why the races in Colorado, North Carolina and Iowa are trending in Democrats favor. Gardner, Tillis and Ernst have records which are an ill fit for running in purple states. Now that voters are being informed of those records they are not doing so well.

If the GOP wins the Senate at 51-49 with all Obama states and NC going blue, that is simply not a GOP wave. Shows more weakness on the GOP side with northern whites.

I predicted the GOP would pick up anywhere from 3 to 6 Senate seats. If they do have a net gain of 6, giving them 51 seats and the majority, I think the scenario you described is the most likely way it will happen.